Fuel injection pump



sept. 2o, 1949.`

M. L. JoHANssoN FUEL INJEcTloN PUMP Filed July 8, 1947 F/G. E.

Patented Sept. 20, 1949 FUEL INJECTION PUMP Martin Leonard Johansson,Enskede, Sweden, asslgnor to Injector Company Aktiebolag, Stockholm,ASweden, a corporation of Sweden Application July s, 1947, serial No.759,561

In sweden July 13, 1946 3 Claims. (Cl. 103-41) The present inventionrelates to a fuel injection pump for internal combustion engines andhaving a plunger which is rotatableabout its longitudinal axis andcarries a lever which, upon being actuated, rotates the plunger toregulate the quantity of liquid fuel injected by each plunger stroke,said plunger being operated by means of a reciprocable tappet' and beingaccommodated in a plunger housing having two chambers, of which the onechamber, vcalled the plunger chamber, accommodates the outer end of theplunger and the other, called the cam shaft chamber, accommodates a camshaft or the like reciprocating the tappet which chambers are separatedby a partition having a through-going bore guiding the tappet.

Such pumps, having a lever on their plunger, have generally been madewith a divided pump casing to enable the mounting of the plunger. Thisinvolves, however, a complication and the present invention has for itsobject to bring about a simplification in this respect and consistssubstantially therein that the pump casing is undivided and made in onepiece and that the bore is provided with a longitudinal slot adaptedtoallow the plunger with its lever to be brought through the cam shaftchamber to the plunger chamber in mounting the pump.

The invention will be described more in detail vwith reference to theaccompanying drawings illustrative of the invention and in which:

Fig. 1 is a transverse vertical section through a pump embodying theinvention; and

Fig. 2 is a fragmentary cross section of the pump casing taken on theline 2-2 of Fig. 1.

As will be seen from the figures the pump casin-g I is made in onepiece. The cam shaft 2 is provided with a cam 5, which imparts to thetappet 6 the axial reciprocating movement thereof. The tappet isaccommodated in the bore 22 in the partition 23 above which there is theplunger chamber 24 and below which there is the cam shaft chamber 25.'I'he tappet actuates in turn the plunger 1 which runs in a plungerbarrel` 8. Above the plunger barrel there is provided a valve housing!)having a delivery valve- I which is held down in closed position bymeans of a compression spring mounted in a nipple II. BarrelI 8 andhousing 9 are held seated in the casing I by the pressure from nipple IIacting through the packing I2. The nipple II at its upper end isconnected to a delivery conduit not shown on the drawing and leading toan injection nozzle of the engine.

The regulation as to the quantity of fuel takes place in known manner byrotating the plunger which is provided with, a control portion I3 havingan oblique control edge. Said control portion covers an overflow orrelief port Il as long as the injection ltakes place. Through rotation,of the plunger the axial length of the control portion is varied inrelation to the overflow port I4 whereby different eiicient lengths ofthe delivery stroke and thus different delivered quantities of fuel areobtained.

The rotation of the piston takes place in known manner by actuating alever I5 force-fitted on to the plunger 1. A vertical portion I6 of thelever I5 runs through a slot in a catching arm I1 rigidly mounted on acontrol rod I8. The latter is accommodated in the casing so as tobedisplaceable axially therein. As 4compared with the known control devicehaving a tooth segment engaging a control rack, it is more advantageousto use a lever I5 as illustrated because the lever will requireconsiderably less force for its shifting and greater tolerances will beallowable in the manufacture.

Hitherto known pumps provided with a con` trol lever have a divided pumphousing in order to facilitate the mounting of the plunger. Thiscomplication hasbeen avoided according to the present invention byproviding an axial slot I9 in the partition of the pump housinglaterally of the bore for the tappet.

In mounting, the barrel 8 is first lowered from the upper end of thepump casing whereupon the spring 20 and the washer 26 are introducedfrom below from the cam shaft chamber 25 and then the plunger 1 with itslever I5 are inserted. The slot I9 is so dimensioned that the leverpasses freely therethrough when the plunger is lifted axially throughthe barrel 8. It is not feasible to mount the plunger in another manner,for instance, by turning it inwardly obliquely through a door 2|,provided the barrel is removed, because the spring 20 is so still' andlong that considerable risk is run of damaging one or more of the parts.

The slot renders possible easy assembly and at the same time enables thepumphousing to be made in asimple and compact manner.

Obviously numerous variations in the design of the different specificelements of the pump may be made without departing from the principlesof the invention, the scope of which is to be understood as embracingall apparatus falling within the purview of the appended claims.

` What is claimed:

1. A fuel injection pump of the plunger type comprising an integral onepiece housing providing a plunger chamber and a cam shaft chamber,

3 said chambers being separated by a partition forming a part of saidhousing, a reciprocable plunger located in said housing with its outerend in the plunger chamber, said plunger being rotatable about itslongitudinal axis to control the amount of fuel delivered by the pumpand having a laterally extending control element associated therewithadapted to engage a control member in the plunger chamber for turningthe plunger, a tappet located in a bore through said partition formoving said plunger, and a cam shaft located in the cam shaft chamberand having a cam for actuating said tappet, said partition having alaterally extending recess communicating with said bore, whereby topermit said plunger and associated control element to be assembled inoperative position in said plunger chamber by being passed `through saidpartition from the cam shaft chamber.

2. A pump as set forth in claim 1, in which said control element is inthe form of a laterally,

ananas extending arm and said recess is in the form of a laterallyextending slot to accommodate the passage of said arm.

3. A pump as set forth in claim 2, in which the outer end of said arm isprovided with an actuating portion substantially parallel with theplunger and said control member comprises an axially movable partengaging the actuating portion of the arm. y

MARTIN LEONARD J OHANSSON REFERENCES CITED The following references areof record in the

